Is Ancient Glass Unbreakable?

The first rule of moving ancient glass? Never pick it up unless you know where you’re going to set it down.

Earlier this winter, glass vessels from the ancient Mediterranean traveled across the Getty Villa Museum from storage into display cases, safely guided by that very principle. The process required a team to gently lift each object out of a foam “bed” and cradle it as carefully as a newborn baby until affixed to its proper place in the case.

The fact that any ancient glass object remains intact enough to be displayed in a museum may seem remarkable—and it is, especially to anyone who has accidentally dropped a drinking glass and had to sweep up the shards. But many ancient glass vessels have survived thousands of years relatively undamaged.

Why many of these vessels are still intact, and how museums keep them safe is due to glass’s cherished, highly protected place in both ancient homes and modern galleries.

The Origins of Ancient Glass

In Europe, Asia, and North Africa, glass production began around 1600 BCE. Creators from Egypt and Mesopotamia mixed sand with natron, a salt compound found in dry Egyptian lake beds, and heated it in a kiln for several days until it turned into glass.

Production was concentrated in just a few workshops in the Mediterranean. Craftspeople from around the region bought glass chunks, then melted them down and formed vessels out of this liquid by pressing it into or around molds and letting it harden.

Glass was valuable, on par with semiprecious stones. At first, the relative scarcity of glass and the laborious process required to make it meant it was reserved for only the highest-ranking members of society, such as the pharaoh and his entourage. They collected small glass flasks to hold substances they thought could protect them from evil spirits or disease, and sometimes the vessels served as offerings to gods and goddesses. Small flasks also held scented oils and perfumes. These special glass items were so treasured that they were often buried alongside their (privileged) owners.

“The ones that are preserved, in good condition, and in one piece were always found in a burial,” says Anastasios Antonaras, an archaeologist and curator at the Museum of Byzantine Culture in Greece and an expert on ancient glass. “So that preserved their integrity.”

The glass-blowing technique we know today—in which an artist shapes hot glass by blowing air at it through a metal tube, instead of manually forming it around molds—was invented in the first century BCE. This method greatly increased glass production, as it used less material and required less time to make each item. Glass objects became more affordable and spread far across the region. People from rich and poor social classes could now buy glass serving bowls, plates, vessels, wine jugs, and beads.

Excavations of ancient homes have unearthed evidence of how these items were used in daily life. But because the glass is usually broken into tiny fragments—these items were seldom buried with their owners, and thereby protected—it’s nearly impossible to put the fragments back together and display them in one piece.

A “Case” Study of Protecting Glass in a Museum

Last fall, the Greek and Roman glass exhibit at the Getty Villa Museum were almost completely deinstalled—that is, over a hundred ancient glass vases, cups, and flasks were taken out of their case so that Antonaras could analyze them for the catalogue he is writing about Getty’s ancient glass collection.

Once he had weighed, measured, and examined each work, select objects were transported to the in-house photography studios for new imaging, or to the conservation lab for additional scientific analysis. Eventually all the objects were returned to their display cases.

Of course, glass is fragile, and needs support inside the case to remain upright. There are a few ways to display glass objects so they don’t topple over. The method chosen depends on the size and shape of the work and how likely it is to fall during an earthquake.

One way to secure an object is to press a few dabs of wax on the bottom of the vessel. This firmly sticks it to the surface of a display platform but can be easily removed later without leaving any residue. This method is appropriate for smaller objects that are in less danger of tipping over.

Another way to secure glass is with a mount. A mount is affixed to a supporting surface in the display case and attached to the object itself. It is barely visible in the gallery and perfectly conforms to the object’s curves, supporting and stabilizing it. Many of the glass vessels are secured to their mounts with SpiderWire, a high-performance fishing line. Some objects may be secured using both wax and a mount for extra stability.

When glass objects aren’t on display, they’re kept in safe storage facilities maintained at optimal temperature and humidity levels to prevent degradation. At Getty, they’re nestled in cushioned drawers lined with Tyvek, a lightweight, breathable material that protects objects from environmental hazards like water, mold, and bacteria. Together, the foam and Tyvek protect glass from breaking or decaying, allowing it to be safely stored well into the future.